1. The Field of the Invention
The present invention relates to solid powder fuels derived from algae and methods for making these fuels and using the fuels to drive a gas turbine.
2. The Related Technology
Renewable resources for energy generation are gaining increasing value as world-wide demand for fossil fuels increases while existing sources are diminished by current consumption rates. Triglycerides form the lipidic energy storage of plant cells and can be extracted from plant biomass to generate an oil product via a solvent extraction or through more complicated processes. Such processes include two-phase extraction of oil from biomass (see e.g., U.S. Pat. No. 6,166,231) and solventless extraction processes (see e.g., U.S. Pat. No. 6,750,048). The resulting oil from these processes is a mixture of triglycerides and various lipophilic pigments, such as carotenoids and xanthophylls. The oil can be used as a fuel, either directly if fed to a burner or an engine, or indirectly if converted to biodiesel via transesterification.
Vegetable oils, derived from plants like soy, canola, sunflower, marigold and palm, can be used as renewable energy resources, usually upon their conversion into biodiesel via transesterification. Oil produced from microorganisms, such as algae, can be used in addition to or as a replacement of vegetable oils. While vegetable oil from plants can be used in the place of some fossil fuels, oil products derived from microorganisms such as algae have the potential to satisfy a higher portion of the global energy demand. Algae can produce 10 to 250 times higher oil yields per acre per year than terrestrial plants. For example, half the entire landmass of the United States would have to be cultivated in soy to produce enough vegetable oil to replace the current US diesel consumption. In contrast, only a fraction of this area would be necessary to cultivate sufficient algae to produce enough oil products to replace current US diesel consumption.
Presently the establishment of systems for the large scale production of oil from plants and microorganisms has not been economically viable. The difficulties in enhancing oil accumulation rates in plants and microorganisms, the development of inexpensive growing systems, and the production of substantially pure forms of oil have made oil produced from organisms more expensive than fossil fuels.